Electric heating and/or cooling blanket



March 12, 1963 E. P. PRICE ELECTRIC-HEATING AND/OR COOLING BLANKET Filed Sept. 15, 1959 4 Sheets-Sheet 1 I I I1 lii ii iii m iliiiii++++++++++++++ 1+1+++++++++I++++++++if +++ill i++++++++++++++i++++i++@ Edward P H/c'e INVENTOR. BY QM WW 19m U U U U U U 1+1++ 111+iiiiiiiiii filii iiiii+ ++++I U U U ELECTRIC HEATING AND/OR COOLING BLANKET Filed Sept. 15, 1959 4 Sheets-Sheet 2 Fig.2

'R Edward 1? Price INVENTOR.

BY 2mm mf may EM March 12, 1963 E. P. PRICE 3,080,723

ELECTRIC HEATING AND/0R COOLING BLANKET Filed Sept. 15, 1959 4 Sheets-Sheet 3 Edward 1'? Price INVENTOR.

BY 2mm March 12, 1963 E. P. PRICE ELECTRIC HEATING AND/OR COOLING BLANKET Filed Sept. 15, 1959 4 Sheets-Sheet 4 1N VEN TOR.

Edward P. Hv'ce II H II n M40162. BY ym, 25m

United States Patent spasms ELECTRIC nEATrNo arm/on COOLING s NKET This invention relates generally to heating and/ or cooling equipment and more particularly to a spread or blanket which may be utilized under any of a plurality of conditions; more particularly, the invention principally relates to the provision of a blanket which may be employed to cool or provide heat for a person in bed.

it is well appreciated that electric heating blankets have been in use for a long time. However, most of the common blankets which have been developed utilize electric heating elements, as in electric toasters or broilers, for the purpose of providing heat. Indeed, this method of heating is probably the least expensive procedure presently available. During the summer months, however, or in warm climates, the electric heating blanket is of course unnecessary and useless. Air conditioners have recently become prevalent to provide a comfortable atmosphere for sleeping. It would be advantageous indeed, if a singular spread or a blanket could be developed for selectively cooling or providing heat. Accordingly, it is the principal object of this invention to provide electrically operated heating and/ or cooling blanket.

The utilization of thermocouples and the Peltier effect associated therewith has long been lmown. The opera tion of the blanket forming the subject matter of this invention is based on the Peltier effect which may be explained briefly by stating that when a direct current is passed across the junction between two dissimilar metals, semi-conductors, or other similar substances, an evolution or an absorption of heat takes place. This effect is different from the evolution of heat (1 13.) due to the resistance of the junction, and is reversible, heat being evolved when the current passes one way across the junction, and absorbed when the current passes in the opposite direction. There is a definite relation between the direction of the thermoelectric current and the sign of the Peltier eifect. If a current be forced across a junction in the same direction as the thermo-electric current flows at the hot junction, the junction will be cooled, that is, heat will be absorbed. Conversely, a current passing in the same direction as the thermoelectric current would flow across the cold junction of the thermoelectric circuit produces or evolves heat at this junction. In general, a thermoelectric current absorbs heat at the hot junction and gives up heat at the cold junction. Therefore, a current produced in the same direction by external means must cool the junction which serves as the hot junction and warms the junction serving as a cold junction. A reversal of flow of this current from the external source will beat the hot junction and cool the cold junction.

By utilizing the above explained vPeltier eifect, thermocouples embedded in the blanket may be activated in a manner such that they cool or heat as desired. Oppositely arranged thermocouples are disposed in a cabinet placed remote from the bed. The cabinet thermocouples are serially connected to the blanket thermocouples being warmed when the blanket thermocouples are cooled and vice versa. Automatic control means in the form of a Patented Mar. 12, 1933 control thermostat is provided for controlling the selective direction of current flow through the thermocouples. Therefore, by adjusting the control thermostat to open and close a pair of switches at the desired temperatures, the blanket will properly serve to cool or heat dependent upon the ambient temperature. Therefore, it is a further object of this invention to provide a novel spread or blanket which automatically reacts to ambient temperature for heating or cooling dependent on the level thereof.

The control thermostat includes a bi-metallic arm which is positioned between a pair of normally open switches. When the bi-metallic arm bends to either of its extreme positions, one of the normally open switches is closed to in turn energize a solenoid coil associated therewith for operating switch contacts to direct current in a selective direction through the various thermocouples.

These together with other objects and advantages which will become subsequently apparent reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming a part hereof, wherein like numerals refer to like parts throughout, and in which:

FIGURE 1 is a circuit diagram illustrating a plurality of thermocouples embedded in a blanket, each thermocouple acting to evolve or to absorb heat depending upon the direction of current flow from an external source through the thermocouples. Also illustrated in FIG. 1 is a remotely positioned cabinet which houses the thermocouples which act to evolve heat when the blanket is used for cooling, and to absorb heat when the blanket is used for heating.

FIGURE 2 is a schematic wiring diagram showing in detail the various control elements and connecting circuits.

FIGURE 3 is a representative elevational view at a junction between two dissimilar metals, semi-conductors, or other elements used in forming a thermocouple.

FIGURE 4 is a representative elevational view of one of the protective thermostats used in protecting the blanket or spread from localized overheating.

FIGURE 5 is a vertical sectional view of the control thermostat illustrating the electrical connections, and functional details thereof.

FIGURE 6 is a side elevational view of a bed i lustrating the blanket utilized on the bed, the cabinet positioned remotely therefrom, and the control thermostat within reach of a person on the bed.

FIGURE 7 is a side elevational view of the switching relay, forming a portion of the circuit control system.

FIGURE 8 is a front elevational view of the switching relay illustrating particularly the connections thereto.

FEGURE 9 is a simplified schematic diagram of the blanket, and accessories.

FIGURE 10 is an enlarged fragmentary sectional view of the blanket taken, substantially, along the plane 10 of FIGURE 1.

With continuing reference to the drawings, initial attention is called to FIGURE 9 wherein numeral 16 generally represents the blanket having thermocouples l2 embedded therein. The thermocouples 12 comprise the junction of two dissimilar elements as 14 and to extending from a polarized plug 18. A conventional wall plug 2% is adapted to be connected to a conventional alternating current source which is converted to direct current and 2 wherein a fuller explanation of the basic system of FIGURE 9 is illustrated. In FIGURES l and 2, again numeral lltl generally represents the blanket including numerous thermocouples 12 embedded therein. The thermocouples 12 are particularly illustrated in FIGURE 3 and comprise a contact junction of two dissimilar elements as 14 and 16. The transformer, generally indi cated as 24, includes a primary coil 38 and a secondary coil 32. A full-wave rectifier, indicated by the numbers 34 and 36, is connected to the secondary coil 32 as particularly illustrated in FIGURE Z. The rectifier is enclosed in a housing generally designatedby 3 7 from which the conductor 38 extends to the firstfix-ed upper contact 48 of the switching relay generally designatedas 42. Conductor 44 extends from the center tap of the secondary coil 32 of the transformer to the third fixed upper contact 46 of the switching relay 42. It will be observed that the direct current output of the rectifier 37 will be delivered across the contacts40and 46.

It will be noted that a connecting wire 48 connects the first fixed upper contact 49 to the third fixed lower contact 50 while the connecting wire 52 connects the third fixed upper contact '46 to the first fixed lower contact 54. A conductor 56 extends from the conductor 38 through a toggle switch 58 located-on the control thermostat, generally designated by numeral 60. A bi-metallic arm 62, supported in the control thermostat 60, is adapted to bridge upper contacts 64 and 66 comprising a first switch 67, while lower contacts 68 and 70 comprise a second switch 71. The upper contact 64 extends through the upper coil 72 of the solenoid switch 42 to the conductor 44connected to the center tap of the secondary coil 32 of the transformer 24 while the lower contact 68 extends through the protective thermostats 78 to the lower solenoid coil 76, which-is likewise connected to the conductor 44. Capacitor 74 is provided to prevent the burning of the contacts of a plurality of protective thermostats 78 interconnected by wire 79 should any of them open. Should one of the protective thermostats 78 open the direct current voltage from the rectifier will be impressed across the red light 80 causing it to burn. Although four thermostats are illustrated in FIGURE 2, it will be appreciated that considerably more are distributed through the blanket as schematically indicated by the dotted line extensions of line 79. A second upper fixed contact 82 of the solenoid switch 42 has a conductor 84 connected thereto extending through a resistor 86 to the pilot thermocouple 88 and back to the third upper fixed terminal 46. A pilot resistor 90 is connected between the third fixed lower terminal 50 and the second fixed lower terminal '92.

An armature 94 extends through the upper and lower solenoid coils 72 and 76 and carries thereon a bridging bar 96 and contact 98. The bridging bar 96 is'adapted to bridge contacts 40 and 82 when solenoid coil 72 is energized and it is adapted to bridge contacts 54 and 92 when solenoid coil 76 is energized. In like manner, the contact .98 may become electrically connected to either of the contacts 46 and 56. The dissimilar elements of the blanket thermocouples 14 and 16 are respectively connected to the contact 98 and bridging bar 96; that is, the various thermocouples 12 in the blanket are connected across the bridging bar 96 and contact 98.

A capacitor 100 is connected across the contacts 68 and 70 to prevent arcing and capacitor 106 is connected across the contacts 64 and 66 for the same purpose. The green light 102 will burn when contacts 64 and 66 are connected by 62, and indicates that the blanket is absorbing heat or-cooling. The amber light 164 willburn when thecontacts 68 and '76 are connected by 62, and indicates that the blanket is heating.

In FIGURE 1 the details of the thermocouple circuit are illustrated, and it will be noted that the thermocouples 12 embedded in the blanket 10, include a plurality of thermocouples connected in parallel which are arranged in series with thermocouples 108 located in the heat exchanger cabinet 110. It will be noticed that the protective thermostats 78 are also embedded in the blanket and extend in the blanket 10 and are interposed between the various thermocouples.

Attention is now called to the control thermostat, generally designated as 60, and particularly illustrated in FIGURE 5. Therein, it will be noted that the bi-metallic arm 62 is cantilevered at 112 to the control thermostat housing 114. The bi-metallic arm 62 carries bridging elements 116 and 118 adapted to respectively bridge contacts 64 and 66, and 68 and 70. A tripping spring 119 is secured between one end of the bi-metallic arm 62 and the housing 114. When the bi-metallic arm moves ofi of center far enough the spring is moved off centeruntil -it trips and makes a positive contact to 64 and 66 or 68 and 70, depending upon whether the arm moves upor down. As the arm moves back to the central position, the spring is reset. The off-on toggle switch 58is illustrated as extending through the housing 114, interposed in the conductor 56. A screw 120, having a knurled head 122, is threadedly extending through the housing 114 and bears against a cantilever spring 124 which has a fiat portion 126 in contact with the bi-metallic arm 62. It will be apparent that by varying the bearing pressure on the spring124, by means of adjusting the screw 120, the temperature which moves the bi-metallic arm 62 causing it to bridge either of the pairs of contacts, may be varied. The pilot thermostat 88, and the pilot resistor 90, located in the housing 114, are designed to simulate temperature conditions Within the blanket and absorb or supply heat to activate the bi-metallic arm.

Attention is now called to FIGURES 7 and 8 wherein the structure of the solenoid relay 42 is particularly set forth. Initially, it will be noted that the solenoid coils 72 and 76 are provided having the movable armature 94 concentrically located with the coils. Springs 130 and 13:27am provided to assure that the armature 94 is properly centered when neither of the solenoid coils is energized. The armature 94 carries the bridgingmember' 96 and the contact 98, as set forth in FIGURE 2. A panel board 134 is provided on the outside of relay 42. The contacts 40, 82 and 46 comprise the upper set of fixed contacts,

and correspond with the contacts shown in FIGURE 2 'while the contacts 54, 92 and 50 are the lower set of fixed contacts shown in FIGURE 2. The upper contacts on the panel board 134 are designated as 136 and 138 and are connected to the bridging bar '96 and contact 98 carried by the armature 94.

In FIGURE 6, a conventional bed 140 is illustrated utilizing the blanket 10, and having the cabinet 110 positioned remote therefrom. The control thermostat 60 may be disposed on a table as 142 placed adjacent to the bed 140.

In FIGURE 10, across section of the blanket or spread 10 is illustrated, and it will be noted that the dissimilar elements forming the thermocouples 14 and 16 extend parallel with each other between the layers of the blanket 10 with the line 79 extending to the protective thermostats '78 which are interposed between sets of thermocouples.

In operation, the toggle switch 58 on the control thermostat 60 is closed so that the bi-metal arm 62, when bent by the simulated blanket temperature, may bridge either of the sets of contacts 64 and 66, or 68 and 70. It, of

, course, will be appreciated that by utilizing the screw 120,

the, temperature level at which the bi-metallic arm 62 bridges the contacts may be varied. Referring to FIG- URE 2, when either of the sets of contacts are bridged, one of the solenoid coils 72 or 76, will be energized to .move the armature 94 to bring the bridging bar 96 and contact 98 either up or down. When the armature goes up, for instance, direct current will flow through the thermocouples 14 and 16 in one direction so as to remove heat from the blanket; while if the armature 94 is moved down, direct current will flow through the thermocouples in the opposite direction which will deliver heat to the blanket. It will be appreciated that the control thermostat 69 provides a constant control of blanket temperature through the action of the thermocouple 88 when the blanket is cooling, and through the action of the resistor 90 when the blanket is heating. The protective thermostats 73 are normally closed, and accordingly, when the bi-metal arm 62 is bridging the contacts 68 and 76, the solenoid coil 76 will be energized through the serially connected protective thermostats 78. Should a fold or folds exist in the blanket, causing local hot spots, one of the protective thermostats 78 will open. This will open the heating circuit to the blanket which will in turn impress rectifier voltage across the red light 102 causing it to burn. The capacitor '74- is placed in the circuit to prevent arcing and burning of the contact points of the protective thermostats 78. When the heating circuit is broken by the opening of one of the protective thermostats 78. the solenoid coil 76 is deenergized causing the solenoid switch to assume the neutral position. This switch will not again close, in the heating position, until the blanket has cooled sufliciently to permit the opened protective thermostat 78 to reclose. This cycle will be repeated until the fold Or folds are removed from the blanket. The lights 102 and 104 indicate whether the blanket is cooling or heating, respectively. That is, with the bi-metallic arm 62 in the lower or heating position, the contacts 68 and '76 will be bridged. This will short out the green light 1592 and impress rectifier potential across the amber light 104 thus causing only the amber light to burn. The reverse is true when the bi-metallic arm is in the upper or cooling position and in this position the green light will burn.

From the foregoing, it is thought that one skilled in the art should clearly appreciate the significance of the various portions of the invention. It will be appreciated that the blanket may be utilized for serving any of a various number of functions in which temperature control is desirable.

The foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described. Also, since various and sundry materials can be successfully used in construction, it is not desired to limit the invention to the use of any specified materials. Accordingly all suitable modifications and equivalents may be resorted to which fall within the scope of the invention as claimed.

What is claimed as new is as follows:

1. A heating and/ or cooling spread comprising an area of flexible material, a plurality of thermocouples embedded in said material, and control means for applying direct current selectively in either direction across said thermocouples for effecting an absorption or an evolu tion of heat, said control means being automatic and responsive to desirable spread temperature, and thermostatic protection means associated with said control for preventing heating beyond a predetermined temperature, said control means include a bi-metallic arm, a pair of normally open switches positioned proximate to, and on either side of, said arm, and adapted to be closed by said arm, and a solenoid operated relay associated with each of said switches for controlling a set of contacts for selectively directing said current through said thermocouples, or for interrupting the flow of such current as directed by the operations of the control thermostat.

2. A system for heating and/or cooling flexible material comprising, two sets of operatively interconnected h thermocouples for respectively absorbing and evolving heat in response to passage of electrical current therethrough, one set of thermocouples being embedded in the flexible material and heat exchange means located in nonconductive heat transfer relation to the flexible material for operatively mounting the second set of thermocouples.

3. The combination of claim 2, including control means operatively connected to the sets of thermocouples for selectively applying electric current thereto in either direction effecting absorption or evolution of heat in said one set of thermocouples.

4. The combination of claim 3, wherein said heat exchange means includes heat removal means for dissipating heat evolved by the second set of thermocouples when said one set is cooling the flexible material and heat generating means operatively connected to the control means for heating the second set of thermocouples when said one set is heating the flexible material.

5. The combination of claim 2, wherein said heat exchange means includes heat removal means for dissipating heat evolved by the second set of thermocouples when said one set is cooling the flexible material and heat generating means for heating the second set of thermocouples when said one set is heating the flexible material.

6. A heating and/ or cooling spread comprising an area of flexible material, a plurality of thermocouples embedded in said material, control means for applying direct current selectively in either direction across said thermocouples for eflecting an absorption or an evolution of heat, and means located in non-conductive heat transfer relation to the flexible material and operatively connected to the thermocouples for removal of the heat therefrom.

7. The combination of claim 6 wherein said control means is automatic and responsive to desirable blanket temperatures.

8. A heating and/ or cooling spread comprising an area of flexible material, a plurality of thermocouples embedded in said material, control means for applying direct current selectively in either direction across said thermocouples for effecting an absorption or an evolution of heat, and means non-conductively located with respect to said flexible material and operatively connected to the thermocouples and control means to effect removal of said heat, and thermostatic protection means associated with said control means for preventing local heating of said flexible material beyond a predetermined temperature.

9. The combination of claim 8 wherein said control means includes a bimetallic arm, a pair of normally open switches positioned proximate to and on either side of said arm, and adapted to be closed by said arm, and a solenoid operated relay associated with each of said switches for controlling a set of contacts for selectively directing said current through said thermocouples or for interrupting the flow of such current as directed by the operations of the thermostatic protection means.

10. In a device suitable for controlling the temperature adjacent a living body in a spread to be placed in contact therewith, comprising flexible supporting means, fi st semiconductive junction means embedded in said supporting means and connected in series with second semi-conductive junction means for passing of direct current there through to exhibit the Peltier eifect, said first junction means being disposed adjacent at least one surface of the flexible supporting means, and heat removal means operatively connected to said second semi-conductive junction means for conduction of heat generated therein externally of the flexible supporting means.

11. The combination of claim 10, wherein said heat removal means includes, heat exchanger means operatively mounting said second junction means in non-conductive relation to the flexible supporting means for removal of heat when generated therein.

12. In a device suitable for controlling the temperaturerofv a body incontact therewith, comprising flexible; supporting means being relatively.non-conductive with; respect to the passage of heat and electrical current there through, semi-conductor junction means embedded in said flexible supporting means, control means operatively connected to the semi-conductor junction means operative to porting means and control means for heat transferwith respect to the semi-conductor means.

UNITED; STATES PATENTS Dewey Oct. 11, Youhouse Nov. 2, Don' kle Apr. 18, Terry July 19, Danielson Ian. 26, McMahon May 31, Suits; July 11,

FOREIGN PATENTS Germany Mar. 26, 

2. A SYSTEM FOR HEATING AND/OR COOLING FLEXIBLE MATERIAL COMPRISING, TWO SETS OF OPERATIVELY INTERCONNECTED THERMOCOUPLES FOR RESPECTIVELY ABSORBING AND EVOLVING HEAT IN RESPONSE TO PASSAGE OF ELECTRICAL CURRENT THERETHROUGH, ONE SET OF THERMOCOUPLES BEING EMBEDDED IN THE FLEXIBLE MATERIAL AND HEAT EXCHANGE MEANS LOCATED IN NON- 